Alarming rattle can noise from under truck

[DavidC]

That thought did cross my mind, if the check valve is allowing fluid back to the trans from the TC it can take somewhere around 30 secs to refill the TC. Although you would not have any gears at least initially until the TC fills to some level.

 

[Scott6]

That thought did cross my mind, if the check valve is allowing fluid back to the trans from the TC it can take somewhere around 30 secs to refill the TC. Although you would not have any gears at least initially until the TC fills to some level.

Yea I have felt the effects of of that before. In my 2nd gen I had removed the problematic check valve from the heat exchanger fitting. So if it sat too long I had to wait for the converter to fill to get and movement. This noise is not that. I have power, it moves just fine. So there is fluid in the TC still.

Im starting to think by best first move is pickup a trans floor jack, slide it back and check the flex plate cam bolts. From there if I can get the trans out from under the truck I can go form there. While I am it I can at least replace the rear main seal thats been caking forever. So its not a total waste of time.

 

[Ozymandias]

And still no difference if forward or rearward gear is in.
His only does it in forward.

Does the 68RFE operate with the same line pressure forward or rear?
I know the 48 doesn't but how is the 68?

 

[Ozymandias]

I pulled my transmission from under the truck by setting it on a piece of sheet metal, dragging it to the light.
It just passed the frame rails with the truck in 4 jack stands.

 

[Scott6]

And still no difference if forward or rearward gear is in.
His only does it in forward.

Does the 68RFE operate with the same line pressure forward or rear?
I know the 48 doesn't but how is the 68?

Yes, it seems to only make the noise in forward gears. Specifically when moving off the line at lower speeds. However I think I have heard it when moving faster down the road (hard to tell). Also I have heard it a few times when I let off the gas and the truck is slowing down on its own (without the exhaust break running). But I can go out and rev it in Park or Natural all day long and it seems to not make the noise.

Interested in an answer to your questions about line pressure in forward gears. I think it is higher since going forward, the custom valve bodies often market the reverse pressure being left alone while they raise the forward pressure.

 

[Ozymandias]

I don't remember, did you take of the exhaust for a try now?

 

[brucejohnson]

It wouldn't surprise me if what you are hearing is a busted vane or two in the torque converter rattling around until fluid gets fully flowing.

 

[Ozymandias]

Just flashed through my brain....
It could be a dry center pilot at the TC that is squeaky within the Flex Plate.
I remember when i installed my new TC that the install manual pointed to this to lightly grease that bore to prevent noise. Was marked as important installment step.

 

[Scott6]

It wouldn't surprise me if what you are hearing is a busted vane or two in the torque converter rattling around until fluid gets fully flowing.

Would it be that loud? the noise is so "tinny", but I get what your saving. Like the noise/issue is like still there but its getting masked by the thick AFT+4 once it gets full submerged. I do feel like its overall not as smooth as it used to be running down the road.

Just flashed through my brain....
It could be a dry center pilot at the TC that is squeaky within the Flex Plate.
I remember when i installed my new TC that the install manual pointed to this to lightly grease that bore to prevent noise. Was marked as important installment step.

Ill make sure to grease that if I end up pop'in on a new converter. Did you do your yourself?

 

[brucejohnson]

Listen to this video. Not exact, but there are similar noises noted. Second video below is closer to what yours sounds like.


Then here is some additional information.
https://itstillruns.com/signs-bad-torque-converter-5073640.html

Then, if you don't get distracted by the sweet exhaust notes:

 

[Scott6]

Listen to this video. Not exact, but there are similar noises noted.

Wow that is pretty spot on, minus all the normal Cummins racket lol. Too bad the user never responded to what the issue turned out to be. intresting stuff for sure.

I did find a local'ish (4 hours away) shop that builds converters. (https://www.greatconverters.com/) I talked to the guy on the phone for a bit, they keep a stock of 68RFE converters on hand. Dual disk, billet backing, slightly lower than stock stall. He said its their go-to converter for the stock-mild tuned deleted working trucks running around all over here. They build them and warranty them at site, so instal shop just sell em. He said $600 over the phone if I bring him the core when I come up to pick it up. Seems like a solid option, still and upgrade, but saving a few hundred for the brand name and I can pick it up myself (and 8 hours of my time, damn!)

EDIT: Calling around, I found a few local builders that that make them for $500-700 so far all have said you want billet, and a little lower than stock stall, all seem to be 300rpms lower.

 

[Scott6]

Curious is there some codes I should have checked for? I have checked with my simple ODBII scanner and my Smarty Jr. Nothing. But IDK if those read trans codes, I think not. But there would be a companion code in the ECU directing me to check the TCM I would think. if so, how?

 

[Ozymandias]

There is no TCM, the ECM controls the whole drivetrain.

For your MY i think Alfa OBD would work for fully diagnostics.

 

[Scott6]

you right my bad, wasn't thinking... well I was, just about companion code on my 2nd gen 47re haha.

got under again tonight for a super super thorough rattle check engine off. There’s nothing loose. Starting to plan the trans pull now..

1. Remove exhaust to make more room, it’s easy, I’m likely gonna replace it all anyways. Test cold engine with no pipes to super confirm the cat is not making it.

2. remove shafts

3. Remove transfer case and skid plates

4. Drains trans and pull her out!

5. check flex plate and fix real main seal

6. Assuming I don’t find plate issues, I’m gonna pull the converter. I picked a local shop that builds converters, lots for diesels running around here, they seem to know their stuff. They will also open mine up first and check it for issues. At that point I’ll buy their billet lower stall unit (1900-2000rpm they said), $550.

7. go backwards. I might buy a billet plate just cause. Don’t want to spend the $$$ but it’s hard not to. also shade u joints while their out.

 

[Ozymandias]

Dont take off the exhaust when attempting to pull the transmission.
The Engine is kept in place by the exhaust, balancing on the motor mounts. Without exhaust it tips down on one or the other side.
There is almost no weight from the engine on the transmission mount, so the exhaust has an easy task to keep the engine on its place.

All you need is a super long ratchet extension to loosen the upper bell bolts.

You are doin this the first time?

 

[Scott6]

Dont take off the exhaust when attempting to pull the transmission.
The Engine is kept in place by the exhaust, balancing on the motor mounts. Without exhaust it tips down on one or the other side.
There is almost no weight from the engine on the transmission mount, so the exhaust has an easy task to keep the engine on its place.

All you need is a super long ratchet extension to loosen the upper bell bolts.

You are doin this the first time?

Makes sense, I’ll leave the exhaust, thanks

yea first time. I’ll take my time, planing on it being down a week.

 

[Ozymandias]

Follow these link > https://www.google.com/search?q=bd+diesel+68rfe+install+manual&ie=utf-8&oe=utf-8&client=firefox-b-m

First result from Summitracing is a download link for the Install manual from BD, good detailed. That helps.


And yes i pulled my transmission twice, once for the install of a new Converter and some internals, second time because of a fault part out of the box.

 

[Scott6]

Follow these link > https://www.google.com/search?q=bd+diesel+68rfe+install+manual&ie=utf-8&oe=utf-8&client=firefox-b-m

First result from Summitracing is a download link for the Install manual from BD, good detailed. That helps.


And yes i pulled my transmission twice, once for the install of a new Converter and some internals, second time because of a fault part out of the box.

good stuff man, thanks.

I don’t need the scan tool to relearn for just the converter right? I thought that was just for the clutches and stuff.

 

[Ozymandias]

Yes that is correct to my knowledge.

 

[Scott6]

well I picked up a trans jack from HF (a univerisal 20% worked too!), long ratchet extension set and another pair of 6 ton jack stands (also got %20 for this specific item from this week). I looked at the "ramps" but I decided I like the height flexibility of 6t stands. Not to mention I trust the stands more than I do those plastic ramps.

Trans filters show up today as well, gonna grab Mopar ATF+4 form amazon. For the life of me I cant find the rear main seal I bought ages ago so I ordered a new one. But its not here until next Wednesday

With any luck I will have the trans safely out this weekend for inspection. I can take the converter in during the following week.